Mandatory Piper Service Bulletin

SUMMARY: The FAA are superseding Airworthiness Directive (AD) 96-12-12, which applies to certain Piper Aircraft, Inc. Models PA-31, PA-31-300, PA-31-325, and PA-31-350 airplanes. AD 96-12-12 requires a one-time inspection of the bulkhead assembly at fuselage station (FS) 317.75 for cracks and the installation of one of two reinforcement kits determined by whether cracks were found during the inspection. This new AD requires repetitive inspections of the bulkhead assembly at FS 317.75 for cracks, repair of cracks as necessary, and the installation of a reinforcement modification. This AD was prompted by cracks found in the FS 317.75 upper bulkhead. We are issuing this AD to correct the unsafe condition on these products. DATES: This AD is effective April 15, 2016. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 15, 2016.